Science Fair Project Ideas About Gravity

Scientists such as Galileo, Brahe, Kepler and Isaac Newton laid the groundwork for and developed the concept of gravity. It was Newton who coined the term in the 1600s. Gravity is a natural, invisible force of attraction which draws bodies of mass toward each other and pulls objects downward toward the surface and center of a planet, moon or other massive body. It can be an interesting topic for science fair projects.

Gravity and Weight of Object

If you were to drop two objects from the air, would a heavier object touch the ground before a lighter object? While logic might tell us yes, Galileo proved that both objects would reach the ground at the same time. Students can create and document an experiment for their science fair project which demonstrates the nature of Galileo's experiment. Students can drop objects of similar sizes but different weights from a first-story window, record and chart the timings, take photos and present their results at the science fair. A model and synopsis of Galileo's experiment can also be included.

Warning: Do not drop heavy objects from a high elevation where there is any possibility of the object striking a person or otherwise causing damage.

Gravity, Weight and the Moon

Students can create a science fair project demonstrating the idea of gravity in space, on the moon and the earth. Visitors to the science fair might not be aware that there is gravity on the moon. Students obtain and chart the weights or all students (and teacher) in their classroom. They can then calculate what these weights would be on the moon, which is roughly one-sixth of what it would be on earth. A column could also be included that shows that there is zero weight in space that is apart from the atmosphere of the planets and moon. Students can create a model of the moon and glue toy human figures on it and can use wires to simulate floating in space as well as the fact that gravity on the moon is less than that on the earth.

Candles, Gravity and Equilibrium

Using a candle, a needle, two glasses and saucers, a gravity machine can be created depicting the relationship between gravity and mass. Students cut away the bottom of a long candle to expose the wick. Then they push a needle through the center of the candle. The ends of the needle are then rested on the rims of two glasses. A saucer is placed beneath each wick and the wicks are lighted. The wax drips from each end of the candle irregularly, causing one side to be lighter than the other. The candle tilts downward on one side, which speeds up the rate at which the candle burns on the other side. The candle then dips toward the other side, like a slow moving see-saw. This process will continue until the candle exhausts itself.

Find the Center of Gravity

The center of gravity is the point at which a body can be balanced. It also can be described as the point through which the resultant force of gravity acts. Students can create their science fair experiment on this subject using an 8-by-10-inch piece of cardboard. They should make a hole near the edge of the cardboard and hang the cardboard on a nail, then tie a small weight, such as a fishing sinker, to a piece of string. They should hang the thread on the nail, marking the vertical line on the cardboard with a marker or pencil. They then should make another hole at another spot near the edge of the cardboard and repeat the process. Where the two lines cross is the center of gravity. This is the spot on the cardboard where a pointed object will balance.